SUPPLEMENT INTAKE IS A MOVING TARGET

by: Stephen B. Blezinger
PhD, PAS

Part 2

In the last issue we began a discussion of animal feed or nutrient intake as it affects performance. One of the most common sayings in animal feeding is that we are feeding the averages. If we have a group of 100 head of cattle, regardless of age we have 100 different feed consumption patterns. Just like people, a group of cattle is a group of individuals. Our goal in feeding and supplementation is to standardize intake as much as possible so that this group of 100 head is consuming. It must be understood that a producer can only do so much. This is an inherent situation, i.e. it just is what it is and always will be. But there are some steps and strategies we can take if we understand a little about cattle eating patterns. We will discuss some of these strategies as well as these eating patterns.

Individual Eating Patterns

As mentioned previously, cattle are a lot like people when it comes to how and what they eat. There are some cows that eat more aggressively than others. We see this commonly if we supplement a group of cows periodically (i.e. once per day, three times per week, etc,) this means we are feeding a specific amount of feed to a set number of animals. For instance, let's say a producer is supplementing his 100 head cow herd with four lbs. of range cubes daily. So each day he is putting out 400 lbs. of cubes. Hopefully he is feeding these in a trough since you lose a lot of feed by cubing straight onto the ground. As he begins to feed (opening bags one at a time and dumping them into a trough), the more aggressive cows will be there first and begin eating first, as he empty's more bags the other cows can get to the trough to eat but remember the aggressive ones have been eating first and are continuing to eat even as the more timid cows are only getting started. So over the course of the 10 minutes it takes him to put out eight bags of cubes some cows may eat 10 lbs. of cubes and some may get none at all (remember the table in Part 1?). This creates a whole list of problems including:

1) Some cows can become over-conditioned due to excessive grain intake.

2) These same cows may then eat less hay which causes an overall imbalance and can even lead to bloat or acidosis.

3) Over-conditioning can lead to breeding problems or in pregnant animals can result in bigger than desirable calves which can increase the need to provide assistance at calving or even increased dystocia rates.

4) The cows receiving a lower than targeted supplement intake may lose excessive condition. The weight loss may result in an animal ill equipped to deal with cold weather winter conditions.

5) These same animals may also experience reproductive problems as well, especially with rebreeding. Cattle with body conditions lower than about four have been shown to experience delayed rebreeding post calving.

6) In many cases, these timid animals may be the first calf heifers in the group if these animals are not kept separate. As such, these heifers will not receive sufficient nutrients to support calving, rebreeding and sustained growth during this period.

The troubling part of this picture to the producer is that he believes that he has an adequate nutrition problem and in general, he does. However, because of the variation in intakes he has animals in the group that are either over consuming or under consuming nutrients, either of which can be a significant problem.

So what are some possible solutions to this problem? Several things:

1) First make sure there is adequate bunk or trough space. In a situation such as this, there needs to be at least 18 to 24 inches of bunk space per head.

2) Locate the bunks in a trap that can be closed off while feed is put out. Once feed is in place, the traps can be opened for the cows to come in and have access to feed all at the same time.

3) Cattle should be grouped by age and production status (i.e. first calf heifers, older more mature cows, etc.). Keep in mind that as cattle are regrouped a pecking order will be re-established each time a new group is created.

4) Change to alternate means of supplementation which allows constant access to supplement. This includes a limited, self-fed supplement, liquid feeds, tubs or blocks. There are advantages to each of these as well as disadvantages. One of the greatest benefits is that these methods allow cattle to consume supplement whenever they want and instead of one large feeding each day where problems such as that described above may take place, individual animals can consume multiple feedings per day. This allows better access to all animals as well as stabilizes the nutrient flow into and through the digestive system. This is of significant benefit to ruminant animals.

Multiple Feeding Locations

One way that some producers choose to address the problem with nutrient variability is to provide multiple sources of supplementation. In other words, during the winter feeding season when hay is the primary dietary component for the cow herd, some producers may also provide a mineral supplement, liquid feed or tubs and may even provide a feed supplement from time to time. The argument here is that this is also an answer to the problem as described above. In other words, if they don't get what they need from one source they can get it from another.

The problem here is that cattle cannot balance their own diets. As humans we are considered reasonably intelligent and few of us can balance ours. By providing multiple feeding locations we create a situation where the amount of nutrient intake variability is even greater. Again, our goal is to limit this variability as much as possible.

A more optimal supplementation model is to provide all supplemental nutrients through one delivery system. Per the previous discussion this is also best served by using an intake limiting, self-fed supplement. The three most common sources include:

1) Dry Feed Supplements limited by salt or the more technologically advanced intake limiting systems used by a number of feed companies. Producer experience with these products has varied primarily in terms of actual intake control. Controlling supplemental feed intake in a mature cow is very challenging. Intake limitation using salt is extremely variable not terribly effective. Over time, most cattle can develop a tolerance for salt. In the more technical products, in many cases, to provide adequate intake control to large mature beef cows, the amount of limiting agent needed to accomplish the task may restrict the amount of actual nutrient that can be included or the product becomes cost prohibitive.

2) Liquid Feed Supplements. Target intakes for most liquids will fall in the range of one to three lbs. per head per day with an average intake of about two lbs. per head per day. This is variable in most cases as a direct relationship to the quality and quantity of the base dietary forage available. As hay quality decreases liquid consumption increases. Liquids can be a good source of protein or protein equivalent in the form of non-protein nitrogen (i.e. urea). Liquids are typically not a great source of energy except that in the form of the sugars found in these products. However, as the use of cane molasses decreases and the amount of the various liquid by-products increases, the typical sugar content of these products is diminishing. Other energy sources in liquids include added fat and products such as propylene glycol or glycerol. But in general the energy level from liquids is not significant. Liquids are also limited in terms of the mineral they can deliver. Unless suspension technologies are used (less common, more expensive), insoluble mineral nutrients such as calcium and magnesium cannot be included at adequate levels. Liquids can be a good source of phosphorus, trace minerals and vitamins.

3) Molasses based tubs or blocks. There are a number of different types of products that fall into this category. Of the three sources listed, tubs are, in general, the most expensive. They are, however, one of the most convenient and can provide the greatest level of intake control. Tubs are generally found in two forms, cooked or poured. Cooked tubs use a heat process for drying and hardening the freed material. This creates a very hard product where the intake is commonly limited to .25 to 1 lb. per head per day. Poured tubs utilize a chemical reaction in the feed mix which hardens the product. This tub is not as hard and allows for higher intake, around one to two lbs. per head per day or more. Another type of tub available is referred to as a pressed tub where pressure is applied to the material in the tub to compress and create a harder material. The physical characteristic would be somewhat similar to a pelleted or cubed feed products but in the much larger tub format. Again, this is a softer product and allows for a higher level of intake.

One thing that must be considered is that in certain situations the very low intake products may restrict intake too much. It is important to know what your base forage nutrient levels are so the proper product can be selected to best fit the forage base to which you have access.

A potential downside of many self-fed supplements is that certain additives and medications cannot be included due to regulatory issues. The supplier or manufacturer must be consulted in these situations.

Other options to help reduce intake variability

Other tools can be used to help standardize intake variation. One of the more common of these are the ionophores (Bovatec®, Rumensin®). Research has shown that both of these products, when fed at proper levels can help stabilize intake, especially in high grain feeding situations. On a breeding operation this can be most commonly used in heifer or bull developing programs where higher levels if actual feed are used.

Still other products that have been shown to stabilize intake are some of the microbial products such as yeasts, fungals and bacterial products. The key to using these products are identifying which products are proven to be viable and effective in a situation where they cannot be added at the time of feeding (as is necessary with some bacterial products). In other words, products that can be added at the point of manufacture and retain their viability for a period of time there after are preferable. Those microbials identified as “fermentation products” may actually be more effective in these applications. Products such as yeasts (Saccharomyces cerevisiae) and fungals (Aspergillus oryzae) have been shown repeatedly to have a positive effect on rumen fermentation and can help stabilize intake patterns.

Conclusions

Intake control is not a concept many pasture cattle operators spend much time on (unfortunately). Taking steps to determine how much variation in nutrient intake your herd is exhibiting may answer questions concerning a lack of or certainly inconsistent performance. Take steps such as those outlined above can be helpful in addressing intake issues and improving overall herd performance.

Dr. Steve Blezinger is a management and nutritional consultant with an office in Sulphur Springs, TX. He can be reached at 667 CR 4711, Sulphur Springs, TX 75482, by phone at (903) 352-3475 or by e-mail at sblez@verizon.net. For more information you can visit follow us on Facebook at www.facebook/reveillelivestockconcepts.







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